Radiator Valve Selection Guide:Basic Installation: Use 2 LKD16AN (angle) or LKD16SN (straight) manual valves, nickel plated with screwdriver stops and caps.Basic Upgrade: Use 1 FF16WAC and 1 FF16LAC manual valves, angle only, chrome plated with white handles (FF16WAC is adjustable for balancing, FF16LAC is fixed open but can be closed for service).TRV (Thermostatic Radiator Valves) are available for automatic temperature control of individual radiators: available in 3 body patterns, with or without thermostatic head (sensor). Use in conjunction with LKD or FF.